1. The Field of the Invention
This invention is in the field of instruments for use in medicine and dentistry. More specifically, this invention is in the field of endodontic irrigator tips for irrigating root canals as part of a root canal procedure.
2. The Relevant Technology
To preserve a tooth that has a diseased pulp cavity, it is necessary to prevent bacterial proliferation within the pulp canal of the tooth by removing the diseased or necrotic pulp material from the pulp canal. After the pulp material has been removed or extirpated from a tooth, the pulp cavity is typically filled or obturated with a material such as gutta percha to occlude the pulp cavity and a sealer to seal the pulp cavity. This procedure is referred to as root canal therapy. Root canal cleaning is generally achieved by hand or mechanical instrumentation with files that are configured to bore and cut.
It is also common during the root canal procedure to irrigate a pulp cavity and the various root canals involved using an endodontic irrigator tip. Irrigation assists in removing debris and necrotic material cut by the endodontic files and bores. Disinfecting solutions can also be employed in irrigation, thereby disinfecting the pulp cavity and root canals during the operative procedure.
Although, the irrigant preferably is capable of dissolving or disrupting soft tissue remnants to permit their removal, the irrigant may be any suitable liquid such as water or various alcohols. More particularly, although some degree of debridement is preferred, any fluid may be used to flush debris from the root canal. General examples of appropriate irrigants include hydrogen peroxide, primarily for use in the canals of living teeth, or sodium hypochlorite, primarily for the canals in necrotic teeth. A preferred irrigant is the aqueous sodium hypochlorite solution sold as ChlorCid(copyright) by Ultradent Products, Inc which contains about 2.5-3% NaOCL. The irrigant may also be a chelator or calcium remover such as EDTA solutions or citric acid solutions. A preferred chelator is sold as File-Eze(copyright) by Ultradent Products Inc. which is a 19% EDTA water soluble viscous solution. File-Eze(copyright) is a preferred chelator as it is also a lubricant.
One problem associated with the use of conventional endodontic irrigator tips is the potential for the formation of ledges within the root canal. Ledges can occur when a practitioner attempts to insert the distal insertion end of an irrigator tip as far as the apex of the root canal and the distal insertion end is halted prematurely against the sidewall of the root canal. The downward pressure exerted on the distal insertion end causes the end to dig into the side of the root canal and form a ledge. Such ledges are difficult to bypass; and if the ledge occurs very close to the apex, the ledge may give the practitioner the mistaken impression that the apex has been reached. Accordingly, there is a need for irrigator tips that can be used in root canal surfaces with minimal risk of ledging. There is a further need within the art for different irrigator tips which can be used to clean root canal surfaces that are efficient to manufacture.
It is therefore an object of the invention to provide an improved endodontic irrigator tip.
It is another object of the invention to provide an endodontic irrigator tip having a cannula that can be conveniently used to maneuver within the root canal while delivering an irrigant in a manner that minimizes the potential for ledging and that enables the distal insertion end of the cannula to reach as far as is desired within the root canal.
An additional object of the invention to provide irrigation tips that are efficient to manufacture.
The endodontic irrigator tip of the present invention comprises a cannula extending from a hub. The cannula has a distal portion that has been annealed so that it is more flexible than the remainder of the cannula. The annealed distal portion is preferably only a small segment of the cannula. The rigidity and length of the nonannealed portion of the cannula enables the cannula to be responsive to the movements of the hub and to be moved as desired within the root canal. The flexibility of the annealed distal portion enables the distal portion to optimally adjust to the curvatures of the root canal.
The hub has a body with a proximal end adapted for coupling to a syringe. The hub also has a neck having a proximal end coupled to the distal end of the body. The neck has a distal end which may be configured with a flat face to optimally prevent the placement of the irrigator tip past a desired location. A hollow chamber is located in the hub which is defined by an interior surface. The hollow chamber extends through the body and the neck and has an inlet such that fluid can be received from a syringe.
The cannula has a distal insertion end and a proximal end sheathed within the distal end of the neck. Thus, a portion of the cannula extends from the distal end of the neck with sufficient length to extend into a root canal of a tooth. An interior surface of the cannula defines a conduit in fluid communication with the hollow chamber. The cannula has an orifice located at the distal insertion end thereof. The outlet orifice is defined by a rim that is preferably rounded instead of squared. The rounded rim works in conjunction with the annealed portion so that as the annealed portion is flexed, the rim does not dig into surfaces that it contacts and is able to be advanced within the root canal. A cannula that is not annealed along any portion of its length and that has a rounded rim may also be utilized.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.